The fields "uri", "location", and "url" from ngx_http_upstream_conf_t
moved to ngx_http_proxy_loc_conf_t and ngx_http_proxy_vars_t, reflect
this change in create_loc_conf comments.
The gRPC protocol makes a distinction between HEADERS frame with
the END_STREAM flag set, and a HEADERS frame followed by an empty
DATA frame with the END_STREAM flag. The latter is not permitted,
and results in errors not being propagated through nginx. Instead,
gRPC clients complain that "server closed the stream without sending
trailers" (seen in grpc-go) or "13: Received RST_STREAM with error
code 2" (seen in grpc-c).
To fix this, nginx now returns HEADERS with the END_STREAM flag if
the response length is known to be 0, and we are not expecting
any trailer headers to be added. And the response length is
explicitly set to 0 in the gRPC proxy if we see initial HEADERS frame
with the END_STREAM flag set.
According to the gRPC protocol specification, the "TE" header is used
to detect incompatible proxies, and at least grpc-c server rejects
requests without "TE: trailers".
To preserve the logic, we have to pass "TE: trailers" to the backend if
and only if the original request contains "trailers" in the "TE" header.
Note that no other TE values are allowed in HTTP/2, so we have to remove
anything else.
The module allows passing requests to upstream gRPC servers.
The module is built by default as long as HTTP/2 support is compiled in.
Example configuration:
grpc_pass 127.0.0.1:9000;
Alternatively, the "grpc://" scheme can be used:
grpc_pass grpc://127.0.0.1:9000;
Keepalive support is available via the upstream keepalive module. Note
that keepalive connections won't currently work with grpc-go as it fails
to handle SETTINGS_HEADER_TABLE_SIZE.
To use with SSL:
grpc_pass grpcs://127.0.0.1:9000;
SSL connections use ALPN "h2" when available. At least grpc-go works fine
without ALPN, so if ALPN is not available we just establish a connection
without it.
Tested with grpc-c++ and grpc-go.
The flag can be used to continue sending request body even after we've
got a response from the backend. In particular, this is needed for gRPC
proxying of bidirectional streaming RPCs, and also to send control frames
in other forms of RPCs.
The flag indicates whether last ngx_output_chain() returned NGX_AGAIN
or not. If the flag is set, we arm the u->conf->send_timeout timer.
The flag complements c->write->ready test, and allows to stop sending
the request body in an output filter due to protocol-specific flow
control.
Basic trailer headers support allows one to access response trailers
via the $upstream_trailer_* variables.
Additionally, the u->conf->pass_trailers flag was introduced. When the
flag is set, trailer headers from the upstream response are passed to
the client. Like normal headers, trailer headers will be hidden
if present in u->conf->hide_headers_hash.
The r->out chain link could be left uninitialized in case of error.
A segfault could happen if the subrequest handler accessed it.
The issue was introduced in commit 20f139e9ffa8.
Previously, only the upstream response body could be accessed with the
NGX_HTTP_SUBREQUEST_IN_MEMORY feature. Now any response body from a subrequest
can be saved in a memory buffer. It is available as a single buffer in r->out
and the buffer size is configured by the subrequest_output_buffer_size
directive.
Upstream, proxy and fastcgi code used to handle the old-style feature is
removed.
If during configuration parsing of the geo directive the memory
allocation has failed, pool used to parse configuration inside
the block, and sometimes the temporary pool were not destroyed.
There is no need to calculate hashes of static strings at runtime. The
ngx_hash() macro can be used to do it during compilation instead, similarly
to how it is done in ngx_http_proxy_module.c for "Server" and "Date" headers.
In particular, if a stream object allocation failed, and a client sent
the PRIORITY frame for this stream, ngx_http_v2_set_dependency() could
dereference a null pointer while trying to re-parent a dependency node.
r->headers_in.host can be NULL in ngx_http_v2_push_resource().
This happens when a request is terminated with 400 before the :authority
or Host header is parsed, and either pushing is enabled on the server{}
level or error_page 400 redirects to a location with pushes configured.
Found by Coverity (CID 1429156).
Resources to be pushed are configured with the "http2_push" directive.
Also, preload links from the Link response headers, as described in
https://www.w3.org/TR/preload/#server-push-http-2, can be pushed, if
enabled with the "http2_push_preload" directive.
Only relative URIs with absolute paths can be pushed.
The number of concurrent pushes is normally limited by a client, but
cannot exceed a hard limit set by the "http2_max_concurrent_pushes"
directive.
Previously, when request body was not available or was previously read in
memory rather than a file, client received HTTP 500 error, but no explanation
was logged in error log. This could happen, for example, if request body was
read or discarded prior to error_page redirect, or if mirroring was enabled
along with dav.
This fixes segfault in configurations with multiple virtual servers sharing
the same port, where a non-default virtual server block misses certificate.
Following ad3f342f14ba046c (1.9.13), it is possible that a request where
header was already sent will be finalized with NGX_HTTP_BAD_GATEWAY,
triggering an attempt to return additional error response and the
"header already sent" alert as a result.
In particular, it is trivial to reproduce the problem with a HEAD request
and caching enabled. With caching enabled nginx will change HEAD to GET
and will set u->pipe->downstream_error to suppress sending the response
body to the client. When a backend-related error occurs (for example,
proxy_read_timeout expires), ngx_http_finalize_upstream_request() will
be called with NGX_HTTP_BAD_GATEWAY. After ad3f342f14ba046c this will
result in ngx_http_finalize_request(NGX_HTTP_BAD_GATEWAY).
Fix is to move u->pipe->downstream_error handling to a later point,
where all special response codes are changed to NGX_ERROR.
Reported by Jan Prachar,
http://mailman.nginx.org/pipermail/nginx-devel/2018-January/010737.html.
The capability is retained automatically in unprivileged worker processes after
changing UID if transparent proxying is enabled at least once in nginx
configuration.
The feature is only available in Linux.
If the flag space_in_uri is set, the URI in HTTP upstream request is escaped to
convert space to %20. However this flag is not checked while creating the
default cache key. This leads to different cache keys for requests
'/foo bar' and '/foo%20bar', while the upstream requests are identical.
Additionally, the change fixes background cache updates when the client URI
contains unescaped space. Default cache key in a subrequest is always based on
escaped URI, while the main request may not escape it. As a result, background
cache update subrequest may update a different cache entry.
Inheriting this flag will make the cloned subrequest behave consistently with
the parent. Specifically, the upstream HTTP request and cache key created by
the proxy module may depend directly on unparsed_uri if valid_unparsed_uri flag
is set. Previously, the flag was zero for cloned requests, which could make
background update proxy a request different than its parent and cache the result
with a different key. For example, if client URI contained the escaped slash
character %2F, it was used as is by the proxy module in the main request, but
was unescaped in the subrequests.
Similar problems exist in the slice module.
Previously, the unparsed uri was explicitly allowed to be used only by the main
request. However the valid_unparsed_uri flag is nonzero only in the main
request, which makes the main request check pointless.
If the data to write is bigger than what the socket can send, and the
reminder is smaller than NGX_SSL_BUFSIZE, then SSL_write() fails with
SSL_ERROR_WANT_WRITE. The reminder of payload however is successfully
copied to the low-level buffer and all the output chain buffers are
flushed. This means that retry logic doesn't work because
ngx_http_upstream_process_non_buffered_request() checks only if there's
anything in the output chain buffers and ignores the fact that something
may be buffered in low-level parts of the stack.
Signed-off-by: Patryk Lesiewicz <patryk@google.com>
If a connection with the read delayed flag set was stored in the keepalive
cache, and after picking it from the cache a read timer was set on that
connection, this timer was considered a delay timer rather than a socket read
event timer as expected. The latter timeout is usually much longer than the
former, which caused a significant delay in request processing.
The issue manifested itself with proxy_limit_rate and upstream keepalive
enabled and exists since 973ee2276300 (1.7.7) when proxy_limit_rate was
introduced.
The ngx_http_upstream_process_upgraded() did not handle c->close request,
and upgraded connections do not use the write filter. As a result,
worker_shutdown_timeout did not affect upgraded connections (ticket #1419).
Fix is to handle c->close in the ngx_http_request_handler() function, thus
covering most of the possible cases in http handling.
Additionally, mail proxying did not handle neither c->close nor c->error,
and thus worker_shutdown_timeout did not work for mail connections. Fix is
to add c->close handling to ngx_mail_proxy_handler().
Also, added explicit handling of c->close to stream proxy,
ngx_stream_proxy_process_connection(). This improves worker_shutdown_timeout
handling in stream, it will no longer wait for some data being transferred
in a connection before closing it, and will also provide appropriate
logging at the "info" level.
A zlib variant from Intel as available from https://github.com/jtkukunas/zlib
uses 64K hash instead of scaling it from the specified memory level, and
also uses 16-byte padding in one of the window-sized memory buffers, and can
force window bits to 13 if compression level is set to 1 and appropriate
compile options are used. As a result, nginx complained with "gzip filter
failed to use preallocated memory" alerts.
This change improves deflate_state allocation detection by testing that
items is 1 (deflate_state is the only allocation where items is 1).
Additionally, on first failure to use preallocated memory we now assume
that we are working with the Intel's modified zlib, and switch to using
appropriate preallocations. If this does not help, we complain with the
usual alerts.
Previous version of this patch was published at
http://mailman.nginx.org/pipermail/nginx/2014-July/044568.html.
The zlib variant in question is used by default in ClearLinux from Intel,
see http://mailman.nginx.org/pipermail/nginx-ru/2017-October/060421.html,
http://mailman.nginx.org/pipermail/nginx-ru/2017-November/060544.html.
Previously, nginx failed to move buffer position when parsing an incomplete
record header, and due to this wasn't be able to continue parsing once
remaining bytes of the record header were received.
This can affect response header parsing, potentially generating spurious errors
like "upstream sent unexpected FastCGI request id high byte: 1 while reading
response header from upstream". While this is very unlikely, since usually
record headers are written in a single buffer, this still can happen in real
life, for example, if a record header will be split across two TCP packets
and the second packet will be delayed.
This does not affect non-buffered response body proxying, due to "buf->pos =
buf->last;" at the start of the ngx_http_fastcgi_non_buffered_filter()
function. Also this does not affect buffered response body proxying, as
each input buffer is only passed to the filter once.
